HK1184765B - Security item and method for the authentication and/or identification thereof - Google Patents

Abstract

The present invention relates to a method for the authentication and/or identification of a security item (1) comprising: a transparent or translucent substrate (90); and, on the side of a first surface (90a, 90b) of the substrate, a first image (20), wherein the method comprises the steps of: at least partially stacking the first image (20) of the item (1) and a second image produced by an electronic imaging device, the second image being located on the side of a second surface (90a, 90b) of the substrate, opposite the first surface; and observing authentication and/or identification information of the security item (1) when changing the angle of observation of the first (20) and second stacked images.

Description

Security article and method for authenticating and/or identifying a security article

Technical Field

The invention relates to the field of security articles, in particular to security documents.

Background

Methods relying on retinal persistence to allow motion reconstruction are known in the art. For example, hallucinogens are known which use a cardboard disk perforated with slits, in which the motion is broken down into a series of still images, and rollers support the cardboard disk as it rotates. A western mirror is also known, which consists of a cylinder, in the upper half of which a slit is pierced and which is hidden inside, and in the lower part of which a strip of picture is moved in a disaggregation manner. When the cylinder is rotated, the camera looks through the slit and looks inside, and the picture is animated. Also known are movable mirrors, the operation of which relies on the principle of a western mirror, comprising several mirrors around its central axis to observe motion artefacts.

Furthermore, it is known that methods for forming motion artefacts are described in documents US5901484, US6286873 and US 2005/0183300. These methods make use of motion decomposition principles that allow the reconstruction of motion "within the frame". The support carries several segmented images, for example corresponding to the decomposition of an object in motion or of an animal in motion, and a carrier transparent film is provided on the support, which carrier transparent film supports a network of parallel lines having a given thickness and having spaces between the lines. Relative motion between the segmented image and the network of lines can create motion artifacts.

The superposition of two elements formed by folding an article is also known. In particular, application WO2006/029744 describes the superposition of two optical elements by folding a document, different optical effects being obtained depending on the distance separating said optical elements. Furthermore, application WO02/17242 describes the superposition of a hologram and a hidden information item by folding the article to reveal said hidden information item. Finally, application US2006/0290136 describes superimposing an encoded image and an optical lens by folding the document to decode said image.

Furthermore, a method for identifying documents, such as banknotes, is known from application WO2005/106808, which consists in superimposing a region of the document on an image displayed on a screen, the image originating from a decoding system sent over a network.

Furthermore, a security element is known from application WO2006/018171, which comprises a verification feature, which in transmitted light has a first appearance, and which when the security element is placed on a specific background, for example on a Liquid Crystal Display (LCD), has a second appearance, which is different from the first appearance.

Disclosure of Invention

There is a need to further enhance the security and methods for authenticating and/or identifying security articles, in particular to increase the difficulty of counterfeiting these articles.

It is also desirable to provide a method for authenticating and/or identifying a security article which is easy to implement for the average person, in particular with the aid of the technical tools at his disposal.

Thus, according to one aspect of the invention, the invention proposes to make use of the previously proposed motion decomposition principles to enable authentication and/or identification of security articles by observing the decomposed motion (thereby causing motion artefacts).

Thus, according to one aspect of the invention, the subject of the invention is a method for verifying and/or identifying a security article, in particular a security document, comprising:

-a transparent or translucent substrate, and

a first image located on the side of the first face of the substrate,

the method comprises the following steps:

-superimposing at least partially a first image of the security article with a second image generated by an electronic imager, the second image being located on the side of a second face of the substrate opposite the first face,

-observing an item of authentication information and/or an item of identification information for the security article during a change of the angle of observation of the superimposed first image and superimposed second image.

According to the invention, it is possible to benefit from a method which allows to authenticate and/or identify a security article by reconstructing an authentication information item and/or an identification information item during a change of viewing angle of said superimposed first image and superimposed second image.

The invention may also impart an entertaining and/or eye-catching effect to the user of the security article by way of displaying hidden information items, for example by way of a motion effect or animation effect.

During the change of the viewing angle of the superimposed first image and the superimposed second image a motion effect or animation effect, in particular of the interlaced images, is observed.

Advantageously, the verification information item and/or the identification information item are not available, in particular not visible, for example to the naked eye or by any means, except during a change in the viewing angle of the superimposed first image and the superimposed second image. Thus, authentication and/or identification of the security article can only result from the viewing of the security article during a change in the viewing angle of the superimposed first and second images.

The presentation of the authentication information item and/or the identification information item can be realized by a parallax effect. By changing the viewing angle of the superimposed first and second images, in particular, the user can see a series of images, so that for example an animation effect can be created. In particular, one of the images, for example in the form of a display frame, may allow the human eyes to see a different image at the same time, for example the brain of the observer may be able to reconstruct the movement or observe hidden information items.

Authentication and/or identification of the security article can likewise be achieved by viewing the front or back side of the security article, in particular by viewing the side of the first side and/or the side of the second side of the substrate of the security article.

The change in viewing angle may be effected by movement of the viewer relative to the superimposed first and second images, in particular by movement of the viewer relative to the electronic imager and the security article, with the superimposed first and second images being stationary. As a variant, the change in viewing angle may be achieved by a displacement of the superimposed first and second images relative to the viewer, in particular by a displacement of the security article and a displacement of the electronic imager while the viewer is stationary, preferably the first and second images are stationary relative to each other.

The second image may be projected into its focal plane to overlay the first image. As a variant, the first image may be superimposed on a second image displayed in the plane of the screen of the electronic imager.

The distance separating the first image plane and the second image plane may correspond to the thickness of the substrate. As a variant, this distance corresponds to the thickness of the substrate and of at least one intermediate element between the means for forming the second image and the substrate (for example the thickness of the screen of the electronic imager).

The substrate may or may not extend from one edge of the security article to the other. In particular, the substrate may be located locally in the security article.

The thickness of the substrate may be less than or equal to the thickness of the security article.

The substrate containing the first image may be present in a window of a security article.

Exemplary embodiments of security windows in security articles are described, for example, in the following publications: GB1552853 which discloses windows formed by transparentization, laser cutting, mechanical abrasion or mechanical cutting, among others; EP0229645, which describes the formation of windows on one or both sides of a two-ply paper in the wet-out phase; WO2004/096482, which describes the formation of windows by laser cutting; CA2471379, which describes the formation of a transparent window and the association with a security element; and WO2008/006983, which describes forming a transparent window on a double-ply paper.

The substrate comprising the first image may be present on an area of the security article having reduced opacity. Such a region of reduced opacity may correspond in particular to a region of lesser thickness, a region which becomes transparent or a region comprising at least one layer of a material having lesser opacity. The opacity of the reduced-opacity region will in particular be low enough to allow the first image to be observed in transmission. Preferably, the image is viewable in transmission and reflection.

The second image produced by the electronic imager may be displayed on the electronic imager, for example, on a screen of the electronic imager.

As a variant, the second image may be projected by the electronic imager, for example onto a background or onto a security article. In particular, when the second image is projected onto the background, the first image of the security article may be superimposed onto the second image projected onto the background such that the substrate is located between the first and second images. As a variant, the second image may be projected at least partially onto a face of the substrate on the opposite side of the first image of the security article.

The change in the viewing angle of the superimposed first and second images may be achieved without relative movement between the security article and the electronic imager, for example by a displacement of the viewer relative to the security article and the electronic imager. The substrate may comprise or consist of a thermoplastic such as a polyolefin, for example Polyethylene (PE), polyvinyl chloride (PVC), polyester, polyethylene terephthalate (PET), Polycarbonate (PC), polyester carbonate (PEC), glycol modified polyethylene terephthalate (PETG), Acrylonitrile Butadiene Styrene (ABS); or comprising or consisting of a light-concentrating film, e.g. of the "waveguide" type, e.g. sold under the trade name BAYERA polycarbonate type luminescent film of (1). When a waveguide film is used, it is preferable that the first image is obtained by laser etching.

The substrate may comprise cellulosic fibers, especially paper. In particular, the substrate may be a sufficiently translucent paper to allow viewing of the authentication information item and/or the identification information item, in particular a coated paper.

The substrate may also be made transparent by applying a composition generally containing fat, for example a composition made of oil and a transparent mineral material as described in patent US2021141, or a composition in the form of a wax in combination with a solvent, for example as described in patent US1479437, which makes the substrate temporarily transparent.

The substrate may also be made transparent by the topical application of wax by heat transfer, as described in patent US 5118526.

As described in patent EP0203499, it is also possible to use, for the substrate, a fibrous layer comprising a heat-fusible substance, such as polyethylene, the transparency of which varies under the effect of localized heat.

For example, the thickness of the substrate is between 10 μm and 1mm, for example less than 25 μm.

The security article and the electronic imager may or may not be in contact when the images are superimposed.

The expression "electronic imager" is intended to mean an electronic device that can produce images by display or projection.

For example, the electronic imager may include a screen on which the second image is displayed.

The electronic imager may comprise any known type of screen, such as a computer screen, a television screen, a mobile phone screen, a screen of an electronic book or diary, a screen of a personal digital assistant, a screen of a watch dial, without this list being limiting.

The electronic imager may be a projector with no screen or no screen on which the projection is performed. The projector may project the second image onto a background or onto the security article with the substrate between the first image and the second image.

For example, the electronic imager may be any known type of projector, such as a projector for slides, a video projector, a background projector, a pico projector or a nano projector, such as a miniaturized video projector integrated into a handheld device (e.g. PDA, mobile phone, laptop), a movie projector, without this list being limiting.

The electronic imager may preferably produce a pixilated image, each pixel of which is individually addressable, preferably having at least 256 gray levels or colors, with a resolution of between 50dpi ("dots per inch") and 1000 dpi.

The electronic imager may be a projector that projects visible light, Infrared (IR) light, and/or Ultraviolet (UV) light.

For example, the first image may be at least partially produced by means of a visible ink and/or a luminescent ink (e.g. a fluorescent ink and/or a phosphorescent ink).

The electronic imager may comprise a screen of the LCD ("liquid crystal display") type, a screen of the LED ("light emitting diode") type, a screen of the OLED ("organic light emitting diode") type, a screen of the laser type, a screen of the plasma type, a screen of the electrochromic type, a screen of the FED ("field emission display") type, a screen of the SED ("surface conduction electron emission display") type, a screen of the LCOS ("liquid crystal on silicon display") type or a screen of the cathode ray tube type.

The electronic imager preferably comprises a Liquid Crystal Display (LCD).

The screen may have a resolution of between 50dpi and 600dpi, preferably between 100dpi and 300dpi, for example a resolution equal to 160 dpi.

The first image and/or the second image may have a polarization characteristic.

For example, the electronic imager may generate the second image by means of polarized light, in particular linearly polarized light, circularly polarized light or elliptically polarized light. The electronic imager may include a screen that emits polarized light or may project polarized light.

The security article may comprise a polarizing filter. In particular, the first image can be generated by means of a polarizing filter.

The first image may be generated according to at least one of the following steps:

-forming a perforation or perforations in at least one polarizing filter to form a first image;

-locally heating the at least one polarizing filter, for example by means of a laser, to locally suppress the polarization properties of the polarizing filter and thereby form a first image;

-selectively applying a diffusing material, such as colloidal silica and/or adhesive tape, for example by printing and/or gluing, onto at least one polarizing filter to form a first image;

-carrying out at least one selective etching on at least one polarization filter, optionally with the aid of a mask, by chemical reaction and/or by emitting optical radiation, in particular Ultraviolet (UV) radiation and/or Infrared (IR) radiation and/or laser radiation, to form a first image, in such a way as to locally eliminate the polarization effect of the polarization filter;

applying at least one polarizing effect to a given non-polarizing substrate, in particular in the form of a transparent or translucent polymer film, for example with the aid of an ink comprising a polarizing compound, in particular by printing or coating said polarizing compound, to form a first image; and

at least one composition comprising cholesteric liquid crystals (e.g. by printing or coating, inter alia)Sold under the trade name SICPASuch compositions) are applied to a given non-polarizing substrate, particularly a polymer film, to form a first image.

As a remark, the previously stated steps will be performed to form an image, which is a positive or negative image of the first image, depending on the desired effect.

In particular, an aliphatic polyurethane based on polyether (trade name sold by the company LAMBERTI is called "LAMBERTI"), for example, by printingPU21/S aliphatic polyurethane) is topically applied to at least one polarizing filter.

In the last possibility mentioned above, when during the implementation of the method according to the invention, the composition comprising cholesteric liquid crystals altering the polarized light of the electronic imager is located between the polarizing substrate and the electronic imager, the polarized light is not blocked by the substrate, and when the polarizing substrate is positioned opaque, the areas covered with cholesteric liquid crystals appear transparent.

On the other hand, when the polarizing substrate is positioned between the composition comprising cholesteric liquid crystal and the electronic imager, the cholesteric liquid crystal has an optically variable effect when the polarizing substrate is positioned to be opaque. More generally, the optically variable effect of cholesteric liquid crystals is known by the term "colour shift" effect, the colour of which depends on the angle of observation and the crystals observed especially on a dark (preferably black) background. The "colour shift" effect of cholesteric liquid crystals may constitute an additional security measure for authenticating and/or identifying security articles.

In a particularly preferred example of implementation of the method according to the invention, therefore, the first image is defined by a first polarizing material superimposed on a second polarizing material, the first material being extended in particular according to a pattern corresponding to the first image and the second material being extended in a continuous manner. The first material is preferably a print of cholesteric liquid crystals and the second material is preferably a linearly polarizing substrate.

The expression "pattern corresponding to the first image" is understood to mean that said pattern can form a positive or negative image of the first image.

Advantageously, when the first and second images have polarization properties, there is only a single orientation of one image relative to the other to allow one image to partially obscure the other image. In other words, there is only a single orientation of the first image relative to the second image to prevent the second image from being able to be viewed through the polarized regions of the first image, and vice versa. In practice, the first image and the second image having the polarization characteristics are composed of polarized regions and unpolarized regions. When the first image and the second image are arranged in front of a light source emitting polarized light, there is only a single orientation according to which the polarized areas are opaque.

In particular, for example, where the security article includes a polarizing filter, there is only a single orientation of the first image relative to the second image projected or displayed by the electronic imager through polarized light, which allows the polarizing filter to mask the polarized light of the electronic imager. The polarizing filter may appear opaque, in particular black, only in which case there is preferably a unique orientation of the first image with respect to the second image.

For example, the unique positioning of the first and second images relative to each other as described above can authenticate and/or identify the security item according to a first security level, particularly by the presence or absence of such an orientation that one image obscures the other.

When the first image and the second image are arranged in accordance with the positioning, a change in the viewing angle of the superimposed first image and the superimposed second image enables viewing of the item of authentication information and/or the item of identification information for the security article.

According to a variant embodiment, the first image may be printed with a compound, in particular a liquid crystal, which is visible only when it is arranged in front of an electronic imager emitting polarized light, in particular a liquid crystal display. Advantageously, the first image is transmissive under unpolarized illumination (e.g. under natural illumination) and is only visible under illumination polarized by means of the electronic imager, thereby providing an additional security measure for the security article.

The electronic imager (e.g., a screen of the electronic imager) and/or the security article may include an indicator that may inform a user as to the manner in which the first and second images are arranged relative to one another to obtain the positioning, e.g., visual data.

The electronic imager, for example the screen of the electronic imager, and/or the security article may further comprise data allowing the viewer to know how to view the superimposed first and second images, in particular at what angle the images have to be viewed in order to view the authentication information item and/or the identification information item.

The security article may comprise an integrated microcircuit, such as an RFID (radio frequency identification) chip or an optical chip (activated for example by light generated by an electronic imager), which is able to communicate with the electronic imager in order for the latter to generate an item of information, in particular a display and/or projection item of information, which can inform about the way in which the first and second images are arranged with respect to each other to obtain said positioning.

The security article may comprise an integrated microcircuit, such as an RFID chip or an optical chip, capable of communicating with the electronic imager so that it generates at least one second image, the association of which with the first image may be capable of implementing the method according to the invention. In particular, the electronic imager may generate at least one second image that is associated with the first image of the security article through communication between the electronic imager and the integrated microcircuit.

The electronic imager may detect a change in orientation of the security article relative to the electronic imager. This change in orientation may result in the display or projection of a new, different second image, or the display or projection of an image whose orientation has changed. For example, the new second image may be moved compared to the original second image so that a change in the orientation of the article that causes a change in the viewing angle, for example, of the superimposed first and second images, does not cause any change in the viewing. In particular, by changing the orientation of the security article relative to the electronic imager, in particular by changing the viewing angle, the authentication information item and/or the identification information item may correspond to a constant view, for example always viewing the same image.

Furthermore, the electronic imager may generate at least one second image based on a photograph and/or video of the security article, in particular based on a first image of the security article or based on an identifier (e.g. a logo or serial number) present on the security article. The photograph and/or video may be produced by an electronic imager to which an image capture device (e.g., a digital camera) is connected via a wire-based connection or a non-wire based connection; and/or the photograph and/or video may be transmitted to the electronic imager, for example, from a device for storing data or over a network (e.g., the internet).

The second image may be generated based solely on the photograph and/or video of the security article, or as a variant, the second image may be generated based on the photograph and/or video of the security article and on additional information items (e.g., information items present on the security article, information items present on the photograph and/or video, information items entered by a user, or information items received from a network, such as a security server).

For example, the electronic imager may comprise a program capable of identifying the security item (in particular the first image) and generating, in particular displaying and/or projecting, a second image obtained from a database informing about the second image to be used as a function of the security item (in particular the first image).

The electronic imager may generate a plurality of second images and/or the security article may comprise a plurality of first images, at least one of the plurality of second images enabling the item of authentication information and/or the item of identification information to be observed when it is superimposed on at least one of the first images, and vice versa, according to the method of the invention.

In particular, security articles may be authenticated and/or identified by various types of electronic imagers.

As a variant, a particular electronic imager may authenticate and/or identify various types of security articles, particularly security articles containing different first images.

For example, the first image may be distinguished by its size, colour, shape, or indeed by the spacing between, or thickness of, the frame points and/or frame lines, particularly where the first image is a display frame and/or combined image as defined below.

The second image may also be distinguished by its size, color, shape, or indeed by the spacing between the frame points and/or between the frame lines, or the thickness of the frame points and/or frame lines, especially in the case where the second image is a display frame and/or combined image as defined below; or indeed by the size of the pixels, the pitch between pixels or the colour of the pixels, especially in the case when the second image is a frame formed by the pixels of a screen as described below.

For example, electronic imagers may be distinguished based on their brand, model, resolution, type, i.e. for example based on the screen of a computer, the screen of a television or the screen of a telephone, or the screen of a projector.

The presence of several first images and/or second images enables authentication and/or identification of the security article, irrespective of the differences mentioned above.

For example, the second image generated by the electronic imager may originate from a communication network with which the electronic imager is in communication (e.g., a telephone network, the internet, or an intranet), e.g., the image is downloaded; and/or, for example, the second image may be provided by an electronic imager on a data medium, such as a hard disk, floppy disk, USB key, CD (compact disk) and/or DVD (digital versatile disk). The security article may contain such a data medium, if appropriate. For example, the data medium may be an integrated microcircuit, such as an RFID or optical chip, that communicates with the electronic imager.

The second image may be a goniochromatic image.

The security article may comprise luminescent regions, for example fluorescent and/or phosphorescent regions, and the electronic imager may project a second image onto the security article under Ultraviolet (UV) illumination, the substrate being located between the first and second images.

In particular, the first image may be a luminescent print, for example printed on a black opaque background of the security article onto which the second image is projected under UV illumination. The first image is then only visible under UV illumination.

The first image may also be printed on a luminescent background of the security article so that the first image is visible under both UV illumination and normal illumination.

The first image may be hidden in the pattern of the security article. The first image may also be integrated into or constitute at least part of the pattern of the security article. As an example, the first image constitutes a part of a person's hair displayed on a banknote.

The first image may comprise a presentation frame and the second image may comprise a combined image comprising at least two interleaved images and being associated with the presentation frame, or vice versa.

The term "associated" must be understood to mean that the display frame is advantageously adapted to enable viewing of the various interlaced images of the combined image.

In particular, those skilled in the art will modify the resolution of the electronic imager and/or the second image as well as the first image to allow for viewing of various interleaved images of the combined image.

As described above, the presence of the number of first images enables authentication and/or identification of the security article irrespective of the electronic imager used, and in particular irrespective of the resolution of the electronic imager.

The at least partial superimposition of the first image and the second image enables the successive observation of interleaved images of the combined image by means of the superimposed display frame and the variation of the angle of observation of the combined image. Thus, the security article may be authenticated and/or identified by reconstructing the interleaved image, which reconstructed interleaved image at least partially constitutes the authentication information item and/or the identification information item for the security article.

For example, the reconstruction of interlaced images can cause motion artifacts, particularly animation.

The electronic imager may include a screen, such as those previously described, whose pixels are used, at least in part, to form the second image in the form of a presentation frame. Advantageously, the first image comprises a combined image associated with a presentation frame, which is thus formed at least in part by the pixels of the screen.

In particular, the frame lines and/or the dots showing the frame may be formed by pixels of a screen of the electronic imager.

The screen may include pixels forming at least two presentation frames having different resolutions. In particular, the screen may comprise two display frames having different spacing between frame points and/or frame lines and/or different thickness of frame points and/or frame lines.

The presentation frame may be formed by a continuous multicolour line formed by screen pixels, in particular comprising pixels with three cells (red, green and blue of the RGB type) spaced apart from each other to form a single colour line without pixels, in particular a black line. The pixel may also have four cells, namely red, green, blue and yellow.

In this way, the pixels of the screen may form an intrinsic display frame of the screen without the need to display a particular image on the screen. For example, by turning on the red, green and blue cells of all pixels of the image, the screen is illuminated with white in a uniform manner.

The imager may be used in two ways. In the first case, an image is displayed that corresponds to a non-uniform switching on of the pixels of the imager. In the second case, all pixels of the imager are turned on in a uniform manner and utilize an inherent framework that results from the arrangement of pixel cells within the imager.

Thus, by observing the interleaved image (in which the first image and the second image are superimposed) with a change in the angle of observation of the first image in the form of a combined image and the second image in the form of a display frame, it is possible to make a monochrome animation of the interleaved image that changes according to the angle of observation in the first direction and a multicolor animation of the interleaved image that changes according to the angle of observation in the second direction. The second direction is different from the first motion, preferably the second direction is perpendicular to the first direction.

The combined image and the interlaced image comprised by the combined image may be framed images, in other words various grey levels of the image may be obtained by framing points and/or framing lines. For example, the framed image may be a halftone image, and based on the grouping of frame points, may particularly present a tone scale, such as a gray scale.

The combined image may correspond to a decomposition of the motion of a pattern, such as a text pattern, an alphanumeric marking pattern, an ideographic pattern, an object pattern, a human pattern, and/or an animal pattern. The interlaced images may show continuous position and/or continuous motion of the pattern, such as continuous position and/or continuous motion of an object, a person, and/or an animal.

Advantageously, the combined image may be obtained by superimposing interlaced images, each showing one position of the pattern.

The interlaced image may display hidden information that is continuously presented by a change in viewing angle of the presentation frame and the combined image, which are superimposed.

Preferably, the combined image retains a recognizable aesthetic, in particular to constitute the first authentication element.

The presentation frame may allow the human eye to see different interlaced images at once, e.g. the brain of the viewer can reconstruct the motion or observe hidden information items.

Within the meaning of the present invention, the expressions "framed image" and "presentation frame" must be a specific broad concept covering all types of frames or pseudo-frames comprising juxtaposed contrasting areas, such as light and dark areas distinguishable from each other, the shape of which is not limited to a specific shape.

For example, the combined image and/or the display frame may comprise a set of dots and/or a set of parallel or non-parallel lines, the size and/or mutual spacing of which may be variable or fixed, this arrangement forming successive light and dark zones, for example white and black zones.

In particular, when the combined image and/or the presentation frame comprises a set of dots arranged, for example, according to rows and/or columns, the viewing of the interlaced image can be achieved by a variation of the viewing angle in at least two directions. This requires, in particular, a direction parallel to the rows and a direction parallel to the columns.

The combined image and/or the display frame may in particular comprise a set of lines, preferably mutually parallel lines of defined thickness and mutual spacing. In particular, the lines may have the same thickness and/or the same mutual spacing.

For example, the combined image and/or the display frame may include continuous dark and light bars, such as black and white lines. For example, the thickness of the dark bars of the combined image is equal to the thickness of the light bars of the display frame. For example, the thickness of the light bars of the interlaced image is equal to the thickness of the dark bars of the display frame.

The display frame may comprise opaque strips with optionally non-linear parallel edges. The presence of opaque stripes with non-linear edges makes copying more difficult for counterfeiters.

The display frame may include strip portions of substantially the same color or of the same color as the strips of the combined image and arranged to mask certain strips of the combined image for a desired effect.

Preferably, the area, in particular the length and/or width and/or the maximum dimension, of the display frame may be greater than or equal to the area, in particular the length and/or width and/or the maximum dimension, of the combined image. In this way, a complete reconstruction of the motion resulting from the relative displacement between the combined image and the display frame can be seen.

The display frame may have any shape, for example: a circular shape; an elliptical shape; the shape of a star; polygonal shapes, such as rectangular, square, hexagonal, pentagonal, rhomboidal shapes; or other shapes.

The security article may include a first portion of the display frame or a first portion of the combined image, and the electronic imager includes another portion of the display frame or another portion of the combined image. The security article and the optical imager may be arranged to bring together two separate portions of the display frame or two separate portions of the combined image to carry out the method according to the invention.

According to a variant of the invention, two combined images having different sizes can be associated. The combined image with the smaller size can be particularly repeated, in particular according to a grid consisting of rows and columns, to appear as a background on which the combined image with the larger size is arranged. The associated display frames then comprise a first display frame adapted for the combined image of larger size and a second display frame adapted for the combined image of smaller size. The two different combined images may exhibit similarity and/or complement each other. The two different combined images may in particular be identical and/or symmetrical.

The first image may be transferred to the security article by a printing process such as offset printing, copperplate printing, laser printing, gravure printing, letterpress printing or screen printing.

For example, the first image may be printed by means of a chromatic or achromatic ink, visible to the naked eye, which is opaque or luminescent, in particular fluorescent, thermochromic, photochromic, and has an interference effect, in particular a glittering effect, or an optically variable effect according to the angle of observation (goniochromatic effect), in particular including liquid-crystal inks, metallic or non-metallic inks, magnetic or non-magnetic inks and others, under Ultraviolet (UV) and/or Infrared (IR) rays.

The first image may also comprise metallization and/or demetallization, for example of aluminium. Advantageously, metallization and/or demetallization may be used to avoid counterfeiting by printing. In particular, it is preferred to use metallizations and/or demetallizations with different colors, for example by means of aluminum and copper.

The first image may include a watermark and a pseudo-watermark.

The watermark is made by techniques well known in the art of papermaking. The pseudo watermark, which reproduces the appearance of the watermark by presenting a difference in opacity, can be obtained by mechanical pressing with or without heating and/or by applying a composition which chemically increases the transparency of the paper locally, for example by a transparentizing substance. The density of the fibrous material of the pseudo-watermark may be uniform compared to conventional watermarks.

The first image and the second image may be colored, in particular having different colors.

The first image may be carried by a patch and/or foil comprising the substrate which plays an important role in the security article.

The patch and/or foil may comprise metallization and/or demetallization (e.g. of aluminium) or any type of printing.

The patch and/or the aluminium foil may comprise holographic printing and/or liquid crystals.

The first image may also be carried by a security thread, the security thread comprising the substrate being integrated on a surface of the security article, inside the security article, or as a window in the security article.

The security thread may have a sufficient width to make the first image appear completely in the security thread. For example, the width of the security thread is between 3mm and 20mm, and preferably between 4mm and 10 mm.

The security article and the elements comprised by the security article, such as the first image, the window, the security thread, the patch and/or the aluminium foil, which may or may not comprise the first image, may comprise one or more additional security elements as defined below.

Among these additional security elements, some elements may be detectable by eye under daylight or artificial illumination, without the use of specific devices. These security elements comprise, for example, coloured fibres or coloured flakes or partially or completely metallised or printed lines. These secure elements are referred to as first level secure elements.

Other types of additional security elements can only be detected by relatively simple means, such as lamps emitting Ultraviolet (UV) or Infrared (IR). These security elements include, for example, fibers, flakes, ribbons, threads or particles. The security elements may be visible or invisible to the naked eye, for example, they emit light under 365nm wavelength light from a woodchuck lamp. These secure elements are defined as a second level.

For the detection of additional security elements of other types, more sophisticated detection means are required. For example, these security elements are capable of generating a specific signal when they are simultaneously or non-simultaneously subjected to one or more external stimuli. If appropriate, automatic detection of the signal may authenticate the article. For example, these security elements comprise tracers in the form of active substances, active particles, or active fibers, which are capable of producing a specific signal when subjected to optoelectronic, electrical, magnetic, or electromagnetic excitation. These security elements are defined as a third level.

The security article and its included elements may have a first level, a second level or a third level of security features.

In particular, the first image may be associated with a metallization effect, a luminescence effect (e.g. fluorescence and/or phosphorescence), a thermochromic effect (e.g. thermochromic ink), a magnetic effect, a polarization effect (e.g. liquid crystal ink), without this list being limiting.

The security article may be: payment instruments such as banknotes, checks or restaurant vouchers; identity documents, such as identity cards, visas, passports or driver's licenses; lottery tickets; a ticket; or tickets to cultural events or sporting events; or access cards, such as for accessing restricted areas.

In particular, the security item may be an access card comprising a first image, for example in the form of a combined image, which card holder is present at an access control point, for example of a company, at which point the method according to the invention is carried out, for example by means of a second image in the form of a display frame to authorize access.

According to a further aspect of the invention, the subject of the invention is also a security article, in particular a security document, for carrying out the method defined previously.

According to another aspect of the invention, the subject of the invention is also a method for verifying and/or identifying a security article, in particular a security document, comprising a first image and an integrated microcircuit (in particular an RFID chip and an optical chip), the method comprising the following steps:

-at least partially superimposing a first image of the security article with a second image generated by the electronic imager, the second image being generated upon communication between the integrated microcircuit and the electronic imager; and

-observing an item of authentication information and/or an item of identification information for the security article, in particular by a relative movement between the first image and the second image and/or by a variation of the angle of observation of the first image and the second image which are at least partially superimposed.

According to another aspect of the invention, the subject of the invention is also a method for verifying and/or identifying a security article, in particular a security document, comprising a first image, the method comprising the following steps:

-superimposing at least partially the first image of the security article with a second image generated by the electronic imager, the second image being generated by the electronic imager based on a photograph and/or video of the security article, in particular the first image; and

-observing an item of authentication and/or identification information for the security article, in particular by a relative movement between the first image and the second image and/or by a variation of the angle of observation of the first image and the second image at least partially superimposed.

The photos and/or video may be generated by an electronic imager to which an image capturing device (e.g., a digital camera) is connected, and/or the photos and/or video is transferred to the electronic imager, e.g., by switching from a device for storing data to the electronic imager or by transferring over a network (e.g., the internet) to the electronic imager.

The security article may comprise a transparent or translucent substrate and the first image may be located on the side of the first face of the substrate. The second image may be at least partially superimposed on the first image with the substrate between the first and second images.

According to another aspect of the invention, the subject of the invention is also a security article comprising a first image that can be superimposed on at least one second image produced by an electronic imager, the first image being defined by a first polarizing material.

The first polarizing material may be laminated to the second polarizing material, the first polarizing material preferably being a print of cholesteric liquid crystals and the second polarizing material preferably being a linearly polarizing substrate.

The first image may be defined by providing a partially unpolarized polarizing substrate to form the first image.

The first image may be defined by a print of polarized ink.

The security article may comprise several different first images, each of which may be superimposed onto at least one second image adapted to the first image produced by an electronic imager, the electronic imager having in particular a different resolution.

According to another aspect of the invention, the subject of the invention is also a security article comprising several different first images, in particular for implementing the method as described above, each first image being overlappable onto at least one second image suitable for the first image produced by an electronic imager, in particular having a different resolution.

The security article may be used in the method described previously. The features described in relation to the method according to the invention are applicable to security articles.

According to another aspect of the invention, the subject of the invention is also a method for making a first image of a security article as defined in the preceding, in which:

-depositing a metal layer on an at least partially transparent substrate;

-applying an ink or a lacquer, which may be coloured or matt, onto the metal layer by printing, coating or deposition to form a first image; and

-selective demetallization in the area or areas not covered with ink or lacquer.

The ink or lacquer may be selected to be compatible with the demetallization process.

For example, the demetallization process may correspond to a soda chemical process that can remove the area or areas of the metal not covered by the ink or lacquer.

The demetallization process may also include the application of a lacquer or ink, which may be matt or coloured, and which has optical properties different from those of the metal layer.

The inks can be chosen from macroscopic coloured or colourless inks which are opaque or luminescent (especially fluorescent), thermochromic, photochromic under UV light and/or IR light, have an interference effect, especially a sparkling effect, or have an optically variable effect depending on the angle of observation (goniochromatic effect), especially comprising liquid-crystal inks, metallic inks or non-metallic inks, magnetic inks or non-magnetic inks, and others. Preferably, the ink fluoresces and/or phosphoresces under UV light and/or IR light.

The security article further comprises a security element of the first level and/or the second level, for example as described previously. In particular, the security article may comprise a security element in the form of a print and/or a marker, in particular a thermochromic or photochromic security element.

By virtue of the manufacturing method according to the invention, a first bright, metallic-lustrous image can be observed on a first side of the security article and a first image having the appearance of an ink or lacquer, for example a coloured or matt first image, can be observed on an opposite second side of the security article.

Drawings

The invention will be better understood on reading the following description of non-limiting examples and its implementation, and on reference to the schematic and partial drawings of the attached drawings, in which:

figure 1 shows a block diagram of the steps implemented in an exemplary method according to the invention;

fig. 1a shows in cross-section the change in the viewing angle implemented in the method according to the invention such that the item of authentication information and/or the item of identification information for the security item can be viewed;

figures 2 to 4 show examples of associations of security articles with electronic imagers to implement the method according to the invention;

FIG. 5 shows an exemplary electronic imager displaying an indicator;

figure 6 shows an exemplary security article comprising a security element and an integrated microcircuit;

figure 7 shows a series of interlaced images that can form a combined image;

fig. 8 shows a combined image based on the series of interlaced images of fig. 7;

FIG. 9 shows an exemplary presentation frame that may be associated with the combined image of FIG. 8;

fig. 10 to 14 show an exemplary embodiment of a security article comprising a first image in the form of a combined image or a display frame;

fig. 15 shows an exemplary first or second image containing two different combined images for implementing an example of the method according to the invention;

fig. 16 shows an exemplary first or second image containing a presentation frame associated with the combined image of fig. 15 for implementing an example of the method according to the invention;

figures 17 and 18 show an exemplary first image and an exemplary second image, respectively, each image comprising a presentation frame and a combined image;

figures 19 to 21 show an exemplary implementation of the method according to the invention, the security article comprising a first image in the form of a display frame and a second image in the form of a combined image generated by an electronic imager;

figures 22 and 23 show another exemplary implementation of the method according to the invention, the security article containing a first image in the form of a combined image and a second image in the form of a display frame generated by an electronic imager;

figures 24 to 26 show another exemplary implementation of the method according to the invention; and

figures 27 to 30 show further examples of implementing the method according to the invention.

Detailed Description

A block diagram relating to steps implemented in an exemplary method according to the present invention is shown in fig. 1.

In a first step I, a first image of the security article is at least partially superimposed with a second image generated by the electronic imager, the substrate being located between the second image and the first image.

In a second step II the user moves relative to the superimposed first and second image.

In a third step III, which preferably accompanies the second step II, the user observes an item of authentication information and/or an item of identification information for the security article, which appears during the change in the angle of observation of the superimposed first and second images.

Step I, step II and step III may or may not be performed simultaneously.

Fig. 1a shows in cross-section that the second image 30 is superimposed on the first image 20 comprising a plurality of patterns 20c, the second image 30 being on the side of the second face 90b of the substrate 90, the second face being opposite the first face 90a of the substrate 90, the first image 20 being present on the first face 90a of the substrate 90.

The second image 30, which includes a plurality of patterns 30c, may be projected onto the second side 90b of the substrate 90, for example, or displayed by the electronic imager 10, and the viewer then superimposes the first image 20 on the second image 30 with the first side 90a of the substrate 90 facing itself.

Next, the observer changes the angle of observation of the superimposed first image 20 and second image 30 to observe the item of authentication information and/or the item of identification information, for example in the case of the first image and second image corresponding to the presentation frame and the combined image, observing the reconstruction of the interleaved image.

Examples of associations between the security article 1 and the electronic imager 10 are shown in fig. 2 to 4, which enable such a method to be implemented.

In fig. 2, for example, the electronic imager 10 is a computer screen on which the second image 30 is displayed.

For example, the security article 1 is in the form of a banknote and includes a first image 20 produced on a transparent or translucent substrate 90 of the security article. The substrate 90 may be located locally on the security article 1, as shown for example in figures 2 and 3, or the substrate 90 may extend from one edge of the security article 1 to the other, as shown for example in figure 4.

According to the steps described in fig. 1, the security article 1 is placed on the screen of the electronic imager 10 so that the first image 20 is at least partially superimposed on the second image 30, with the first face 90a of the substrate 90 facing the viewer, who then moves relative to the security article 1 and the screen of the electronic imager 10 to view the item of authentication information and/or the item of identification information for the security article 1.

In fig. 3, the electronic imager 10 is, for example, in the form of a digital projector that projects a second image 30 onto a background 50, for example, onto a wall of a room.

The security article 1 containing the first image 20 may then be at least partially superimposed on the second image 30 projected onto the background 50, with the first face 90a of the substrate 90 facing the viewer, behind the background 50, on the side opposite to the side on which the second image 30 is projected, to carry out the steps described with reference to figure 1.

In figure 4 the electronic imager 10 is a projector which projects the second image 30 directly onto the security article 1, the security article 1 comprising a transparent or translucent substrate 90 extending over the entire surface of the security article 1.

As in the example of fig. 4, the second image 30 may be projected, for example in the form of a "W", onto an area of the security article 1 where the first image 20 is not present. The security article 1 may then be folded upon itself, for example according to the direction of arrow F, to superimpose the first image 20, such as in the form of "a", onto the second image 30 projected by the electronic imager 10, whereupon the substrate 90 is located between the first image 20 and the second image 30, to carry out the steps described in figure 1. Thus, the portion of the security article 1 containing the first image 20 may be folded back over the portion containing the second image 30 (which remains stationary), in such a way that the second image 30 is positioned between the imager 10 and the first image 20. In particular, during observation, the security article 1 folded back on itself remains fixed and the distance between the security article and the electronic imager 10 remains unchanged, for example the observer can move relative to the security article 1.

In a variant (not shown), the second image 30 is projected directly onto the side of the second face 90b of the substrate 90, directly superposed with the first image 20 of the security article 1.

In fig. 5, a modified embodiment is shown, wherein the electronic imager 10 is a screen displaying several second images 30a, 30b, 30c and 30 d.

The second images 30 a-30 d may have different attributes, such as different shapes, different colors, different sizes, different frame points or frame lines.

Advantageously, the second images 30a to 30d differ in order to allow at least one of them to be associated with at least one first image 20 present on the security article 1. In such a way, for example, more diversified security articles 1 having different respective first images can be authenticated and/or identified, corresponding to the various second images 30a to 30 d.

As a variant, the security article 1 comprises several different first images 20, such as can be seen in fig. 14, and the electronic imager 10 generates one or more second images 30. In such a way, a given security article 1 can be authenticated and/or identified, for example, on a more diverse variety of different electronic imagers, in particular with electronic imagers having different resolutions. In such a way, the two advantages described previously can be combined.

The electronic imager 10 may display one or more indicators 40a, 40b, 40c and 40d that can advise the user as to the manner in which the security article 1 is positioned, depending on the imager.

In particular, the indicators 40a to 40d are able to know where to position the upper right corner of the security article 1 so that the first image 20 of the security article 1 is correctly superimposed on the second image 40a, 40b, 40c or 40d displayed on the screen of the electronic imager 10.

Fig. 6 shows a security article 1 containing an additional security element 51 of any known type, for example one of those previously described, for example a luminous security thread.

Furthermore, the security article 1 may comprise an integrated microcircuit 52, such as an RFID or optical chip, which may communicate with the electronic imager 10 to control the display of indicators such as those previously described or to disseminate items of information about the manner of positioning of the first and second images.

In particular in the previously described example, the first image 20 may comprise the presentation frame 3 and the second image 30 may comprise the combined image 2, the combined image 2 comprising at least two interlaced images 2a, as mentioned above, the combined image 2 being associated with the presentation frame 3, or vice versa.

The subsequent figures 7 to 26 illustrate this possibility.

A series of interlaced images 2a that can form a combined image 2 is shown in fig. 7, the combined image 2 being visible in fig. 8, fig. 8 showing a pattern in the form of a elephant in this example.

For example, the interlaced image 2a corresponds to four different poses of the elephant, and thus enables the decomposition of the elephant's motion.

Each interlaced image 2a may comprise a series of parallel lines as shown, spaced in a regular or irregular manner, and having varying thicknesses.

The images 2a are superimposed on each other to form a combined pattern corresponding to the combined image 2.

Fig. 9 illustrates an exemplary presentation frame 3, which may be associated with the combined image 2 of fig. 8.

For example, the display frame 3 has a rectangular shape and comprises a set of parallel lines spaced in a regular or irregular manner and having a varying thickness.

The display frame 3 has an area, length and width which are larger than the area, length and width of the combined image 2 so that the full motion of the elephant can be more easily seen during the relative displacement between the combined image 2 and the display frame 3.

In this example, the combined image 2 and the presentation frame 3 comprise sets of alternating light and dark lines, in particular black and white lines, but also other lines. For example, the lines may be coloured and different for the combined image 2 and the display frame 3.

Fig. 10 to 14 show an exemplary embodiment of a security article 1 for implementing the method according to the invention.

In fig. 10, the security article 1 comprises a window 4 in which a transparent or translucent substrate 90 and a first image 20 in the form of a display frame 3 are presented. For example, the first image 20 may be formed by printing (especially copperplate printing), metallization, or demetallization.

In figure 11 the security article 1 comprises a patch 5 comprising a transparent or translucent substrate 90, in which patch 5 a first image 20 is presented in the form of a display frame 3, for example the patch 5 comprises holographic printing.

The display frame 3 may comprise holographic printing and/or metallisation and/or demetallisation.

In fig. 12, the security article 1 comprises a security thread 6 comprising a transparent or translucent substrate 90, on which security thread 6 a first image 20 appears in the form of a combined image 2.

In fig. 13, the security article 1 comprises a security thread 6, on which security thread 6 a first image 20 is presented in the form of a display frame 3.

The security thread 6 comprises a transparent or translucent substrate 90. The display frame 3 may extend from one edge of the security article 1 to the opposite edge.

In fig. 14, the security article 1 comprises a security thread 6 comprising a number of first images 20 in the form of combined images 2. The first image 20 is generated in such a way that: the security article 1 may be used with different electronic imagers, in particular electronic imagers having different resolutions, each first image 20 being adapted to the particular resolution of the electronic imager.

The security thread 6 also comprises a transparent or translucent substrate 90 over its entire surface.

The several first images 20 appearing on the security article 1 and arranged on the security thread 6 may simplify the method for manufacturing the security article 1 by incorporating the security thread 6 into a substrate, in particular a fibrous substrate. In particular, the incorporation of data is not necessarily required.

In all the examples described previously, the combined image 2 and the presentation frame 3 are exchangeable.

The security thread 6 may be introduced into the security article 1 in a conventional manner, for example on the surface, or internally or as a window.

The combined image 2 and/or the display frame 3 may also comprise a polarizing filter. The security article 1 may be authenticated and/or identified by the electronic imager 10 emitting polarized light.

In fig. 15, a second image 30 (or first image) is diagrammatically shown, which comprises two different combination images 21 and 22. For example, second combined image 22 is a symmetric image of first combined image 21 after modification of its dimensions to yield a mesh of combined images 22 organized into rows and columns.

Fig. 16 shows the corresponding first image 20 (or second image), shown diagrammatically in fig. 16 in the form of a display frame 3 of interlaced images 21a and 22 a. The display frame 3 comprises an association of two base frames 3c and 3d in which the interlaced image 21a and the interlaced image 22a can be observed respectively. For example, the frame 3c comprises a series of black strips alternating with strips of the frame 3d, the frame 3d being constituted by alternating black and white lines with a small pitch.

In fig. 17, a first image 20 (or a second image) is diagrammatically shown in the form of a combined image 22 arranged around a display frame 31 according to a network of combined images 22.

In fig. 18, a second image 30 (or first image) is shown diagrammatically in the form of a combined image 21 surrounded by a display frame 32.

Fig. 19 to 21 show an exemplary implementation of the method according to the invention.

In this example, the electronic imager 10 takes the form of a mobile phone, for example, on which a second image 30 (visible in fig. 21) in the form of the combined image 2 is displayed.

Furthermore, the security article 1 comprises a polarising filter comprising a transparent or translucent substrate 90 on which the first image 20 in the form of the display frame 3 is formed.

Figure 20 shows a security article 1 superimposed on a second image 30, the security article 1 containing the first image 20 in the form of a display frame 3, the second image 30 being in the form of a combined image 2 produced by an electronic imager 10, the electronic imager 10 emitting polarised light.

The user moves the security article 1 so that the security article 1 is in a crossed orientation which allows the opacity of the polarisation filter associated with the polarised light to be observed.

Then, as can be seen in fig. 21, the eyes of the observer are opposite to the free axis F₁And axis F₂The formed plane is moved to change the viewing angle of the superimposed first and second images to observe the animation of the interlaced image. The user moves while maintaining the relative orientation of the frame with respect to the screen.

Such a method may authenticate and/or identify the security article 1 according to several security levels.

Positioning the display frame 3 containing the polarizing filter according to an orientation such that the opacity of the polarizing filter is observable provides a first level of security, the observation being visible only on a screen emitting polarized light, for example a screen of the LCD type.

A second level of security is provided by the animation of interlaced images presented by changing the viewing angle of the presentation frame 3 and the combined image 2.

Fig. 22 and 23 show a further exemplary implementation of the method according to the invention.

In this example, the electronic imager 10 is preferably a screen comprising a plurality of pixels, in particular of the LCD type.

Fig. 22 shows, in part, the electronic imager 10 in the form of an LCD screen containing a plurality of pixels, and fig. 23 shows an enlarged portion of fig. 22.

The set of pixels of the screen forms a second image 30 in the form of a presentation frame 3.

As can be seen in fig. 23, the screen may contain a regular arrangement of pixels arranged in horizontal and vertical stripes. In particular, the horizontal lines may comprise three pixels P of different colors (e.g. RGB)₁、P₂And P₃Is repeated.

Furthermore, as can be seen in fig. 23, the horizontal lines of pixels may be separated by black regions N that do not contain pixels.

In this way, when the combined image 2 of the security article 1 is superimposed onto the screen of the electronic imager 10 containing the display frame 3, the change in the horizontal direction of the viewing angle may display a multicoloured animation such that some interlaced images are observed, and, after rotating the combined image 2 by 90 °, the change in the vertical direction of the viewing angle may display a monochrome animation such that other interlaced images are observed.

According to a variant, the combined image 2 and the display frame 3 are made to allow the observation of an animation formed by a variation of the observation angle according to two different directions, in particular perpendicular. Such an effect is obtained, for example, by a display frame 3 consisting of a matrix of rows and columns of dots, for example by a square-shaped display frame, or by a suitable combined image 2, such as the combined image 2 shown in fig. 25.

The electronic imager 10 may correspond to a screen of a mobile phone, such as a mobile phone screen having a resolution of 160dpi, resulting in a display frame whose pixels are spaced at about 159 μm intervals.

The combined image 2 present on the security article 1 may appear in a through-window of the security article 1 which is sealed by a transparent plastics strip which constitutes the substrate 90 of the security article. The transparent plastic strip may have the characteristics of a circular polarizing filter.

A security article 1 comprising a polarising transparent plastics strip on which a combined image 2 is formed may be manufactured to retain polarisation characteristics over the component areas of the combined image, for example having a number of successive helical positions. The combined image 2 can thus be made in the manner described previously, for example by printing a strip of plastic with a special ink that provides polarizing properties or by heating the areas where polarizing properties need to be removed, for example by using a laser.

Fig. 24 to 26 show a further exemplary embodiment of the method according to the present invention.

In this example, the electronic imager 10 in the form of a screen contains a first portion 30a of the second image in the form of a display frame 3a, as shown in fig. 24.

The security article 1 comprises a further portion 30b of the second image in the form of a display frame 3b, for example a further portion 30b in an at least partially transparent window of the security article. Furthermore, the security article 1 comprises a first image 20 in the form of a combined image 2 in a window of the security article, the window comprising a transparent or translucent substrate 90, as seen in figure 25.

When the security article 1 is folded upon itself so that the combined image 2 overlies the portion 3b of the display frame with the substrate 90 between the first image 20 and the portion 3b of the display frame, and in turn overlies the electronic imager 10, so that the combined image 2 and the portion 3b of the display frame overlie the portion 3a of the display frame formed on the screen of the electronic imager 10, the method according to the invention may be implemented by changing the viewing angles of the portion of the security article 1 containing the combined image 2 and the portion of the security article 1 containing the portion 3b of the display frame to allow reconstruction of the display frame and viewing of the interleaved image, as shown in figure 26. Advantageously, the combined image 2 allows to observe an animation or two animations due to a change of the viewing angle in two different directions, respectively (in particular in two perpendicular directions).

An exemplary security article 1 in the form of a passport is shown in fig. 27, which includes a first image 20 and an RFID chip 60 printed on a transparent or translucent substrate 90 in the form of a combined image 2.

The chip 60 is capable of communicating with the electronic imager 10 (not shown) to enable generation of the second image 30 in association with the first image 20.

In particular, during use for authenticating and/or identifying the passport 1, the first image 20 is illuminated with an electronic imager. The chip 60 contains an information item that is transmitted to the electronic imager, which then projects a second image according to the information item.

Fig. 28 shows a further exemplary embodiment of the method according to the present invention.

In this example, the security article 1 in the form of a passport contains a first image 20 in the form of a combined image 2, which first image 20 is obtained by metallising a transparent plastic film which is inserted into the passport through the window 4.

The passport 1, in particular the combined image 2, is photographed or filmed by a digital camera 70 belonging to or associated with the electronic imager. The recognition program may then recognize the combined image 2 and retrieve a second image from the database that is associated with the first image. For example, the database store is stored on a secure server. The second image thus obtained is displayed and/or projected by the electronic imager so that the passport 1 can be verified and/or identified by changing the viewing angle of the superimposed first and second images.

Fig. 29 shows a security article 1 in the form of a banknote.

The security article 1 comprises a first image 20 printed on a transparent or translucent substrate 90, the first image 20 representing, for example, a human face, the first image 20 comprising a combined image 20 on the level of human hair.

For the purpose of authenticating and/or identifying the banknote 1, it is possible, for example, to photograph the banknote, in particular the first image 20, and thus to generate a second image associated with the first image, the second image being obtained on the basis of a photograph of the banknote.

For example, the electronic imager is a mobile phone capable of taking a picture of a banknote, and a program inside the mobile phone may download a second image associated with the first image, after which the second image may be displayed on the screen of the mobile phone to implement the method according to the invention.

According to a variant, the program inside the mobile phone may generate the second image associated with the first image.

Fig. 30 shows an exemplary security article comprising a light emitting region in cross-section.

The security article 1 comprises a transparent or translucent substrate 90 on a first side 90a of which substrate 90a luminescent layer 81, in particular a fluorescent layer and/or a phosphorescent layer, is printed. For example, the substrate 90 is completely covered with the light emitting layer 81.

Further, the first image 20, for example, in the form of a combined image, is printed with a black opaque layer on the light emitting layer 81.

An associated electronic imager (not shown) capable of projecting a second image 30 (not shown) on the side of the second face 90b of the substrate 90 under Ultraviolet (UV) illumination or normal illumination, the second image 30 at least partially superimposed on the first image 20, the first image 20 being visible under normal illumination or UV illumination.

The term "comprising" is synonymous with "comprising at least one".

Claims (85)

1. A method for authenticating a security article (1), the security article (1) comprising:

-a transparent or translucent substrate (90), and

-a first image (20) on the side of the first face (90a) of the substrate,

the method comprises the following steps:

-superimposing at least partially a first image (20) of the security article (1) with a second image (30) produced by an electronic imager (10), said second image (30) being located on the side of a second face (90b) of the substrate, opposite to said first face; and

-observing an item of authentication information for the security article (1) during a change in the angle of observation of the superimposed first image (20) and second image (30).

2. A method as claimed in claim 1, wherein the substrate (90) extends from one edge of the security article (1) to the other.

3. A method according to claim 1, wherein the substrate (90) is located locally on the security article (1).

4. The method of any of claims 1 to 3, wherein the second image (30) is displayed on the electronic imager (10).

5. The method of claim 4, wherein the second image (30) is displayed on a screen of the electronic imager (10).

6. The method of any of claims 1 to 3, wherein the second image (30) is projected by the electronic imager (10).

7. The method of claim 6, wherein the second image (30) is projected on a background (50) or on the security article (1).

8. The method of claim 1, wherein a motion effect or animation effect is observed during a change in the viewing angle of the superimposed first image (20) and second image (30).

9. The method of claim 8, wherein the motion or animation effect is a motion or animation effect of the interlaced image (2 a).

10. The method of claim 1, wherein the electronic imager (10) comprises a Liquid Crystal Display (LCD).

11. The method of claim 1, wherein the first image (20) and the second image (30) have polarizing properties.

12. The method of claim 11, wherein the electronic imager (10) produces the second image (30) by polarized light and the first image (20) comprises a polarizing filter.

13. The method according to either one of claims 11 and 12, wherein, before viewing the item of authentication information during a change in viewing angle of the superimposed first (20) and second (30) images, the first (20) and second (30) images are positioned according to the orientation of one image relative to the other to allow one image to partially obscure the other image.

14. The method of claim 1, wherein the security article (1) comprises a plurality of different first images (20) and/or the electronic imager (10) produces a plurality of different second images (30a, 30b, 30c, 30 d).

15. The method of claim 1, wherein the first image (20) comprises a presentation frame (3) and the second image (30) comprises a combined image (2), the combined image (2) comprising at least two interlaced images (2a), the combined image (2) being associated with the presentation frame (3).

16. The method of claim 1, wherein the first image (20) comprises a presentation frame (3) and the second image (30) comprises a combined image (2), the combined image (2) comprising at least two interlaced images (2a), the presentation frame (3) being associated with the combined image (2).

17. The method of claim 15, wherein the electronic imager (10) comprises a screen, pixels of which are at least partially used to form the second image (30) in the form of a display frame (3).

18. The method of claim 17, wherein the frame lines and/or dots of the presentation frame (3) are formed by pixels of a screen of the electronic imager (10).

19. The method of claim 17 or 18, wherein the display frame (3) is formed by a continuous multicoloured line formed by pixels of a screen of the electronic imager (10).

20. A method as claimed in claim 19, wherein the lines forming the display frame (3) comprise pixels having three elements, a red element, a green element and a blue element, the pixels being spaced from one another to form a single colour line free of pixels.

21. The method of claim 20, wherein the non-pixel, monochrome lines forming lines of the display frame (3) are black lines.

22. The method according to claim 1, wherein the security article (1) comprises an integrated microcircuit (60) in communication with the electronic imager (10) for the electronic imager (10) to generate the second image (30) in association with the first image (20).

23. The method according to claim 1, wherein the electronic imager (10) generates at least one second image (30) based on a photograph and/or video of the security article (1).

24. The method of claim 23, wherein the electronic imager (10) generates at least one second image (30) based on a photograph and/or video of the first image (20).

25. The method of claim 1, wherein the first image (20) is defined by a first polarizing material superimposed on a second polarizing material.

26. A method according to claim 25, wherein the first polarizing material is a print of cholesteric liquid crystal and the second polarizing material is a linearly polarizing substrate.

27. A method for identifying a security article (1), the security article (1) comprising:

-a transparent or translucent substrate (90), and

-a first image (20) on the side of the first face (90a) of the substrate,

the method comprises the following steps:

-superimposing at least partially a first image (20) of the security article (1) with a second image (30) produced by an electronic imager (10), said second image (30) being located on the side of a second face (90b) of the substrate, opposite to said first face; and

-observing an item of identification information for the security article (1) during a change in the angle of observation of the superimposed first image (20) and second image (30).

28. A method according to claim 27, wherein the substrate (90) extends from one edge of the security article (1) to the other.

29. A method according to claim 27, wherein the substrate (90) is located locally on the security article (1).

30. The method of any of claims 27 to 29, wherein the second image (30) is displayed on the electronic imager (10).

31. The method of claim 30, wherein the second image (30) is displayed on a screen of the electronic imager (10).

32. The method of any of claims 27 to 29, wherein the second image (30) is projected by the electronic imager (10).

33. The method of claim 32, wherein the second image (30) is projected on a background (50) or on the security article (1).

34. The method of claim 1, wherein a motion effect or animation effect is observed during a change in the viewing angle of the superimposed first image (20) and second image (30).

35. The method of claim 34, wherein the motion or animation effect is a motion or animation effect of the interlaced image (2 a).

36. The method of claim 27, wherein the electronic imager (10) comprises a Liquid Crystal Display (LCD).

37. The method of claim 27, wherein the first image (20) and the second image (30) have polarizing properties.

38. The method of claim 37, wherein the electronic imager (10) produces the second image (30) by polarized light and the first image (20) comprises a polarizing filter.

39. The method according to any one of claims 37 and 38, wherein, before viewing the item of identification information during a change in viewing angle of the superimposed first (20) and second (30) images, the first (20) and second (30) images are positioned according to the orientation of one image relative to the other to allow one image to partially obscure the other image.

40. The method according to claim 27, wherein the security article (1) comprises a plurality of different first images (20) and/or the electronic imager (10) produces a plurality of different second images (30a, 30b, 30c, 30 d).

41. The method of claim 27, wherein the first image (20) comprises a presentation frame (3) and the second image (30) comprises a combined image (2), the combined image (2) comprising at least two interlaced images (2a), the combined image (2) being associated with the presentation frame (3).

42. The method of claim 27, wherein the first image (20) comprises a presentation frame (3) and the second image (30) comprises a combined image (2), the combined image (2) comprising at least two interlaced images (2a), the presentation frame (3) being associated with the combined image (2).

43. The method of claim 41, wherein the electronic imager (10) comprises a screen, pixels of which are at least partially used to form the second image (30) in the form of a display frame (3).

44. The method of claim 43, wherein frame lines and/or dots of the presentation frame (3) are formed by pixels of a screen of the electronic imager (10).

45. The method of claim 43 or 44, wherein the display frame (3) is formed by a continuous multicoloured line formed by pixels of a screen of the electronic imager (10).

46. A method according to claim 45 wherein the lines forming the display frame (3) comprise pixels having three elements, a red element, a green element and a blue element, the pixels being spaced apart to form a single colour line free of pixels.

47. A method according to claim 46 wherein the non-pixel, monochrome lines of lines forming the display frame (3) are black lines.

48. The method according to claim 27, wherein the security article (1) comprises an integrated microcircuit (60) in communication with the electronic imager (10) for the electronic imager (10) to generate the second image (30) in association with the first image (20).

49. The method according to claim 27, wherein the electronic imager (10) generates at least one second image (30) based on a photograph and/or video of the security article (1).

50. The method of claim 49, wherein the electronic imager (10) generates at least one second image (30) based on a photograph and/or video of the first image (20).

51. The method of claim 27, wherein the first image (20) is defined by a first polarizing material superimposed on a second polarizing material.

52. A method according to claim 51, wherein the first polarising material is a print of cholesteric liquid crystal and the second polarising material is a linearly polarising substrate.

53. A method for authenticating and identifying a security article (1), the security article (1) comprising:

-a transparent or translucent substrate (90), and

-a first image (20) on the side of the first face (90a) of the substrate,

the method comprises the following steps:

-superimposing at least partially a first image (20) of the security article (1) with a second image (30) produced by an electronic imager (10), said second image (30) being located on the side of a second face (90b) of the substrate, opposite to said first face; and

-observing an item of authentication information and an item of identification information for the security article (1) during a change in the angle of observation of the superimposed first image (20) and second image (30).

54. A method according to claim 53, wherein the substrate (90) extends from one edge of the security article (1) to the other.

55. A method according to claim 53, wherein the substrate (90) is located locally on the security article (1).

56. The method of any of claims 53 to 55, wherein the second image (30) is displayed on the electronic imager (10).

57. The method of claim 56, wherein the second image (30) is displayed on a screen of the electronic imager (10).

58. The method of any of claims 53 to 55, wherein the second image (30) is projected by the electronic imager (10).

59. The method of claim 58, wherein the second image (30) is projected on a background (50) or on the security article (1).

60. A method as claimed in claim 53, wherein a motion effect or animation effect is observed during a change in the viewing angle of the superimposed first (20) and second (30) images.

61. The method of claim 60, wherein the motion or animation effect is a motion or animation effect of the interlaced image (2 a).

62. The method of claim 53, wherein the electronic imager (10) comprises a Liquid Crystal Display (LCD).

63. The method of claim 53, wherein the first image (20) and the second image (30) have polarizing properties.

64. The method of claim 63, wherein the electronic imager (10) produces the second image (30) by polarized light and the first image (20) comprises a polarizing filter.

65. The method of any one of claims 63 and 64, wherein the first image (20) and the second image (30) are positioned according to an orientation of one image relative to the other image to allow one image to partially obscure the other image before viewing the item of authentication information and the item of identification information during a change in viewing angle of the superimposed first image (20) and second image (30).

66. The method of claim 53, wherein the security article (1) comprises a plurality of different first images (20) and/or the electronic imager (10) produces a plurality of different second images (30a, 30b, 30c, 30 d).

67. The method of claim 53, wherein the first image (20) comprises a presentation frame (3) and the second image (30) comprises a combined image (2), the combined image (2) comprising at least two interlaced images (2a), the combined image (2) being associated with the presentation frame (3).

68. The method of claim 53, wherein the first image (20) comprises a presentation frame (3) and the second image (30) comprises a combined image (2), the combined image (2) comprising at least two interlaced images (2a), the presentation frame (3) being associated with the combined image (2).

69. The method of claim 67, wherein the electronic imager (10) comprises a screen, pixels of which are at least partially used to form the second image (30) in the form of a display frame (3).

70. The method of claim 69, wherein frame lines and/or dots of the presentation frame (3) are formed by pixels of a screen of the electronic imager (10).

71. The method of claim 69 or 70, wherein the display frame (3) is formed by a continuous multicoloured line formed by pixels of a screen of the electronic imager (10).

72. A method according to claim 71 wherein the lines forming the display frame (3) comprise pixels having three elements, a red element, a green element and a blue element, the pixels being spaced apart to form a single colour line free of pixels.

73. The method of claim 72 wherein the non-pixel, monochrome lines forming lines of the display frame (3) are black lines.

74. The method according to claim 53, wherein the security article (1) comprises an integrated microcircuit (60) in communication with the electronic imager (10) for the electronic imager (10) to generate the second image (30) in association with the first image (20).

75. The method of claim 53, wherein the electronic imager (10) generates at least one second image (30) based on a photograph and/or video of the security article (1).

76. The method of claim 75, wherein the electronic imager (10) generates at least one second image (30) based on a photograph and/or video of the first image (20).

77. The method of claim 53, wherein the first image (20) is defined by a first polarizing material superimposed on a second polarizing material.

78. A method according to claim 77, wherein the first polarising material is a print of cholesteric liquid crystal and the second polarising material is a linearly polarising substrate.

79. A security article (1) for implementing the method of any one of claims 1, 27 and 53, the security article comprising a first image (20) superimposed on at least one second image (30) produced by an electronic imager (10), the first image (20) being defined by a first polarising material.

80. The security article of claim 79 wherein the first polarising material is superimposed on the second polarising material.

81. The security article of claim 80 wherein the first polarizing material is a print of cholesteric liquid crystal and the second polarizing material is a linearly polarizing substrate.

82. A security article as claimed in claim 79 in which the first image (20) is defined by a polarising substrate which provides a local non-polarising to form the first image (20).

83. A security article as claimed in claim 79 in which the first image (20) is defined by a print of polarised ink.

84. A security article as claimed in any one of claims 79 to 83 in which the security article comprises a plurality of different first images (20), each first image (20) being superimposed on at least one second image (30) produced by an electronic imager (10), the second image being adapted to the first image.

85. The security article of claim 84 wherein the electronic imagers (10) have different resolutions.